Hello: Classic and frequent issue, all of these >20 yrs old scopes have NVRAM and backyup batteries failing dso CAL is lost.
The ?????? and errors are the symptom of NV ram battery dead CAL constants lot.
Check schematics for A5 board for your model and serial.
Many long threads on this group and on EEVBLOG.
Search 2465 NVRAM, 2465 A5 board 2465 battery also check for corroded SMD lytics.